Vascular diseases are among the most common fatal diseases. They include, above all, myocardial infarction, which is caused by diseases of the coronary arteries. Where a blockage of coronary arteries occurs as a result of arteriosclerotic plaque, this clinical picture is treated mainly by means of percutaneous transluminal coronary angioplasty (PTCA). Here, the constricted points in the coronary arteries are expanded by means of a balloon catheter. However, clinical studies have shown that this leads in very many patients to a restenosis, and in some of the studies such restenosis formed in 50% of patients. High-frequency rotor ablation angioplasty, which can advantageously be used in particular in fibrotic or calcified or elongated stenoses has been known as an alternative method for some years.
In order to reduce the risk of formation of restenosis, coronary atherectomy is used to achieve rechanneling of stenosed coronary arteries through debulking. The device for performing the atherectomy is a catheter system with a metal casing in which the actual cutting apparatus, the cutter, is located. The cutter, which consists of a conically ground blade, is connected via a flexible connection to a motor outside the patient. The cutting blade is driven by this motor at a speed of 1,500-2,000 rpm. A balloon is mounted on one side of the metal housing, and a window on the contralateral side. During the atherectomy, the balloon is inflated, and the openings and the blade are thereby pressed into the plaque. The rotating blade can now be pushed forward from the outside toward the tip of the atherectomy housing. By this means, the plaque is cut out and the plaque material pushed toward the tip of the atherectomy device. The balloon is then deflated, the atherectomy device rotated a little so that the window points toward another area of the plaque, and the process is repeated. An atherectomy device is known from U.S. Pat. No. 5,895,402.
In U.S. 2005/0203553 A1 a catheter with an integrated OCT sensor for deployment in blood vessels has been proposed, which improves image representation of the stenosis in the near range.
A new imaging method, which is already being trialed in individual clinics, is intravascular magnetic resonance tomography (IVMRI), which is known, for example, from printed publications U.S. Pat. No. 6,377,048, U.S. Pat. No. 6,704,594 and U.S. Pat. No. 6,600,319. The first-mentioned printed publication describes a solution with the aid of an external (i.e. applied outside the body) static magnetic field. In the two last-mentioned printed publications, solutions are described in which the static magnetic field is generated by the catheter and no external magnetic field is required for generating a field. In the case of IVMRI, an MRI catheter, i.e. a catheter for imaging with the aid of magnetic resonance signals, is introduced into vessels under X-ray monitoring and extracted from the vessels manually. Important additional medical information about arteriosclerotic plaque can be obtained through the images of the IVMRI systems. Magnetic resonance imaging is known for its good representation of soft tissue.
In U.S. 2005/018571A1 a device for performing and monitoring artherectomy is described in which an externally rotatingly driven cutting blade, set back so as to protrude into an opening of the catheter tip, can be pressed onto the vessel wall by means of an inflatable balloon arranged on the side opposite the window opening of the catheter sheath, an artherectomy catheter being connected with an OCT catheter to form an integrated assembly.